Bjørn Jahren

• Hausmann, Jean-Claude & Jahren, Bjørn (2019). A simplification problem in manifold topology. L'Enseignement mathématique (LEM). ISSN 0013-8584. 64(1/2), s. 207–248. doi: 10.4171/LEM/64-1/2-8. Fulltekst i vitenarkiv
• Jahren, Bjørn & Kwasik, Slawomir (2018). Whitehead torsion of inertial h-cobordisms. Topology and its Applications. ISSN 0166-8641. 249, s. 150–159. doi: 10.1016/j.topol.2018.09.013. Fulltekst i vitenarkiv Vis sammendrag

  We study the Whitehead torsion of inertial h-cobordisms, continuing an investigation started in [12]. Of particular interest is a nested sequence of subsets of the Whitehead group, and a number of examples are given to show that these subsets are all different in general. The main new results are Theorem 2.5, Theorem 2.6, Theorem 2.7. Proposition 5.2 is a partial correction to [12, Lemma 8.1]. © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/

• Jahren, Bjørn & Sławomir, Kwasik (2015). How different can h-cobordant manifolds be? Bulletin of the London Mathematical Society. ISSN 0024-6093. 47(4), s. 617–630. doi: 10.1112/blms/bdv039. Fulltekst i vitenarkiv
• Jahren, Bjørn & Kwasik, Slawomir (2011). Free involutions on S-1 x S-n. Mathematische Annalen. ISSN 0025-5831. 351(2), s. 281–303. doi: 10.1007/s00208-010-0599-y. Fulltekst i vitenarkiv
• Jahren, Bjørn (2010). Pseudoisotopies and the Bokstedt trace. Geometriae Dedicata. ISSN 0046-5755. 148(1), s. 245–261. doi: 10.1007/s10711-009-9441-7. Fulltekst i vitenarkiv
• Jahren, Bjørn (2009). Involutions on the rational K -theory of group rings of finite groups, Alpine Perspectives on Algebraic Topology. American Mathematical Society (AMS). ISSN 9780821848395. s. 189–202. Fulltekst i vitenarkiv
• Jahren, Bjørn (2009). Pseudoisotopies and the Bökstedt trace. Geometriae Dedicata. ISSN 0046-5755. doi: 10.1007/s10711-009-9441-7. Fulltekst i vitenarkiv
• Jahren, Bjørn & Kwasik, S (2006). Manifolds homotopy equivalent to RP4#RP4. Mathematical proceedings of the Cambridge Philosophical Society (Print). ISSN 0305-0041. 140. Fulltekst i vitenarkiv
• Jahren, Bjørn (2003). Three-dimensional surgery theory, UNil-groups and the Borel conjecture. Topology. ISSN 0040-9383. 42, s. 1353–1369. Fulltekst i vitenarkiv
• Jahren, Bjørn (1999). K-theory, flat bundles and the Borel classes. Fundamenta Mathematicae. ISSN 0016-2736. 161, s. 137–153. Fulltekst i vitenarkiv Vis sammendrag

  Using Hausmann and Vogel's homology sphere bundle interpretation of algebraic K-theory, we construct K-theory invariants by a theory of characteristic classes for flat bundles. It is shown that the Borel classes are detected this way, as well as the rational K-theory of integer group rings of finite groups.

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• Rognes, John; Jahren, Bjørn & Waldhausen, Friedhelm (2013). Spaces of PL Manifolds and Categories of Simple Maps. Princeton University Press. ISBN 9780691157757. 192 s. Fulltekst i vitenarkiv
• Baas, Nils A.; Friedlander, Eric M.; Jahren, Bjørn & Østvær, Paul Arne (2009). Algebraic Topology. The Abel Symposium 2007. Springer. ISBN 9783642011993. Fulltekst i vitenarkiv
• Jahren, Bjørn (2006). Motivic Homotopy Theory. Springer. ISBN 9783540458951. 222 s. Fulltekst i vitenarkiv

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• Jahren, Bjørn (2017). H-Cobordisms and stabilization of diffeomorphisms. Fulltekst i vitenarkiv
• Nerland, Stener; Jørgensen, Kjetil Nordbø; Jahren, Bjørn; Melle, Ingrid; Andreassen, Ole Andreas & Agartz, Ingrid (2016). A Topological Characterisation of Cortical Folding in Schizophrenia and Bipolar Disorder. Fulltekst i vitenarkiv
• Jahren, Bjørn (2016). On the work of Eldar Straume on Transformation Groups. Fulltekst i vitenarkiv
• Jahren, Bjørn (2015). Inertial and non-inertial h-cobordisms. Fulltekst i vitenarkiv
• Jahren, Bjørn (2012). How different can h-cobordant manifolds be? Fulltekst i vitenarkiv
• Jahren, Bjørn (2012). How different can h-cobordant manifolds be? Fulltekst i vitenarkiv
• Jahren, Bjørn (2012). H-cobordant manifolds. Fulltekst i vitenarkiv
• Jahren, Bjørn (2011). Relationships between h-cobordant manifolds. Fulltekst i vitenarkiv
• Jahren, Bjørn (2011). Fra musikk til algebra og geometri. Fulltekst i vitenarkiv
• Jahren, Bjørn (2011). Exotic structures on manifolds. Fulltekst i vitenarkiv
• Jahren, Bjørn (2011). Eksotiske sfærer. Fulltekst i vitenarkiv
• Jahren, Bjørn (2009). Litt om topologisk fikspunktteori. Fulltekst i vitenarkiv
• Jahren, Bjørn (2008). Topological classification of free involutions on S^1xS^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2008). Topological classification of free involutions on S^1xS^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2008). Topological classification of free involutions on S^1xS^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2007). Topological classification of free involutions on S1xSn. Fulltekst i vitenarkiv
• Jahren, Bjørn (2007). Topological classification of free involutions on S1xSn. Fulltekst i vitenarkiv
• Jahren, Bjørn (2006). Lefschetz-Nielsen teori og homotopi-fikspunkter. Fulltekst i vitenarkiv
• Jahren, Bjørn (2006). Trace invariants for fixed and periodic points. Fulltekst i vitenarkiv
• Jahren, Bjørn (2006). Manifolds homotopy equivalent to RP^4#RP^4. Fulltekst i vitenarkiv
• Jahren, Bjørn (2006). Trace invariants for fixed and periodic points. Oberwolfach Reports. ISSN 1660-8933. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). On manifolds homotopy equivalent to RP^4 x RP^4. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Topological classification of free involutions on S^1 x S^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). On manifolds homotopy equivalent to RP^4#RP^4. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Some calculations of rational homotopy of diffeomorphism groups. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). On topological mansilds doubly covered by S^1xS^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Fixpoints and homotopy fixpoint of maps. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Introduction to surgery theory. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Topological classification of free involutions of S^1xS^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Topological classification of free involutions on S^1xS^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Classification of free involutions on S^1xS^3. Fulltekst i vitenarkiv
• Jahren, Bjørn (2005). Topological classifications of free involutions on S^1xS^n. Fulltekst i vitenarkiv
• Jahren, Bjørn (2004). A homological formula for the Lefschetz-Reidemeister torsion. Fulltekst i vitenarkiv
• Jahren, Bjørn (2004). Geometri og geometrier i dimensjon 3 (To foredrag). Fulltekst i vitenarkiv
• Jahren, Bjørn (2004). Homotoy fixpoints and Nielsen-Lefschetz theory. Fulltekst i vitenarkiv
• Jahren, Bjørn (2001). Problems and results in low-dimensional surgery. Fulltekst i vitenarkiv
• Jahren, Bjørn (2001). On surgery in dimension 3. Fulltekst i vitenarkiv
• Jahren, Bjørn (2001). 3-dimensional surgery, UNil-groups and the Borel conjecture. Fulltekst i vitenarkiv
• Jahren, Bjørn (2001). On surgery in dimension 3. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Hvorfor er det så trangt i dimensjon 4? Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Hvorfor er det så trangt i dimensjon 4? Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Flat bundles and Borel classes in K-theory. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Kirurgiobstruksjonen i dimensjon 3. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Topology and geometry of 3-manifolds. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Hvorfor er det så trangt i dimensjon 4? Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Mozart, menuetter og terningkast. [Radio]. "WOK" : NRK, P2. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Mozart, menuetter og terningkast. [Radio]. Metropol TV. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Flat bundles and Borel classes in K-theory. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Mozart, menuetter og terningkast. [Radio]. "Midt i musikken" : NRK radio, P2. Fulltekst i vitenarkiv
• Jahren, Bjørn (2000). Mozart, menuetter og terningkast. [Radio]. Metropol TV. Fulltekst i vitenarkiv
• Jahren, Bjørn (1999). 3-dimensional surgery and the Borel conjecture. Fulltekst i vitenarkiv Vis sammendrag

  The Borel conjecture asserts that closed aspherical manifolds are determined up to homeomorphism by their fundamental groups. The general conjecture is still open, but it has been proved for classes of manifolds satisfying certain geometric properties. Using surgery theory in dimension three and stabilizing, we show that the assertion holds for new classes of manifolds, and we also discuss the possibilities of counterexamples to Borel's conjecture. This is joint work with Slawomir Kwasik, Tulane University.

• Jahren, Bjørn (2011). Geometric Structures in Dimension two. Nettsidene til kurset MAT4510. Fulltekst i vitenarkiv
• Jahren, Bjørn (2010). Supplementary notes for MAT4520, Spring 2010. Internt på kurssider. Fulltekst i vitenarkiv
• Jahren, Bjørn (2007). geometric structures. Matematisk institutt, kurssidene til MAT4510. Fulltekst i vitenarkiv
• Jahren, Bjørn & Kwasik, Slawomir (2006). Free involutions on S^1xS^n. Institut Mittag-Leffler. Fulltekst i vitenarkiv
• Jahren, Bjørn; Rognes, John & Waldhausen, Friedhelm (2006). Spaces of PL manifolds and categories of simple maps. Institut Mittag-Leffler. Fulltekst i vitenarkiv
• Jahren, Bjørn & Kwasik, Slawomir (2000). 3-DIMENSIONAL SURGERY THEORY, UNiL-GROUPS AND THE BOREL CONJECTURE. Universitetet i Oslo. Fulltekst i vitenarkiv
• Jahren, Bjørn & Kwasik, Slawomir (1999). 3-dimensional surgery, UNil and the Borel conjecture. Fulltekst i vitenarkiv
• Jahren, Bjørn (1995). IGUSA'S EXACT SEQUENCE AND THE BÖKSTEDT TRACE. Universitetet i Oslo. Fulltekst i vitenarkiv
• Jahren, Bjørn (1993). K-THEORY, FLAT BUNDLES AND THE BOREL CLASSES. Universitetet i Oslo. Fulltekst i vitenarkiv
• Dundas, Bjørn Ian & Jahren, Bjørn (1991). The K-Theories of Gersten/Swan and Waldhausen Agree on most Simplicial Rings. Universitetet i Oslo. Fulltekst i vitenarkiv
• Jahren, Bjørn (1973). SMOOTHING THEORY AND TOPOLOGY OF PL/O. Universitetet i Oslo. Fulltekst i vitenarkiv

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